demarcate.js is a jQuery plugin which allows you to directly edit a pages HTML code and generate the equivalent Markdown code from it.
demarcate.js provides you with in-page editing and a toolbar to allow for basic formatting of the HTML elements. After editing, it allows you to generate the markdown which can then be used in any possible way.
For the time being, demarcate.js supports basic Markdown functions but support for extension is still limited.
License: MIT License